Speaking-telephone



B. GRAY. Speaking Telephone. No. 233,343. Patented Oct. 19, I880.

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NJEI'EIIS, PHOTO LITHOGRAPHER. WASHINGTON, Dv O.

SPECIFICATION forming part To all whomit concern:

Be it known that I,';ELIISHA GRAY, a citizen cago, in the county of Qook and State of Illinois, have invented certain new and useful Improvements, in Speaking- Telefiiones, of which the following is a specification.

My present invention; more especially relates to 'and constitutesan' improvement upon my bipolar telephone, forwhich an application for Letters Patent of the United States was filed by me March 21,1878, and patented May 21, 1878, as No. 204,029.

The object of my present improvement is, while preserving the portable feature of the instrument, (so as to enable-it to be handled with facility,) to cause an increased volume and clearness of sound, which ends I attain by combining three or more diaphragms with proper circuit-connections and with a common mouth-piece, around which they are arranged.

The subject-matter claimed is hereinafter specified.

The accompanying drawings represent so much of my improvedmultipolar telephone as is necessary to illustrate the subject-matter herein claimed as constructed in the best way now known to me. Itsdetails of construction and arrangement may,'however, be varied in various wayswithout departing from the spirit of my invention, andsome of the improvements may be used without the others in telephones of differentoonstruction. I

Figure 1 represents a plan or top View of a multipolar or quadruplex telephone composed of two single bipolar telephones, and having four diaphragms arranged around a common a mouth-piece, each diaphragm having its own t; magnet. Fig. 2 represents a side elevation thereof, partly in central longitudinal section therethrough on the line 2 2 of Fig. 1. Fig. 3 shows the arrangement of the circuitconneotions.

My improved apparatus embodies all that is shown in my bipolar telephone (hereinbefore mentioned) in duplicate, having two permanent U-shaped or horseshoe steel magnets, A, arranged at right angles to each other, coustituting the handleof the instrument, rubber disks B, helices 0, soft iron cores D, check-nuts cl, diaphragms E, screw-caps F,

' UN ITED STATES of the United States, and a resident of Ohi-- PATENT OFF CE.

ELISHA GRAY, CHICAGO, ILLINOIS.

SPEAKlNG-TELEPHON E.

of Letters Batent No. 233,343, dated October 19, 1880.

Applicatian filed May a, 1878.

clamping-rim gs G, and a common mouth-piece, H, terminatingat the junction of four branch tubes, h, each branch being secured to its respective cap, so as tobring its mouth opposite the center of its respective diaphragm.

Each diaphragm, it will be observed, is mounted upon one pole of its respective permanent magnet, which magnets are arranged transversely to each other to constitute the handle or support of the instrument, and are secured at their neutral axis or point of junction by suitable fastenin gs. The diaphragms are likewise arranged around the mouth-piece with their edges nearly touching each other, and with their surfaces inclined to an angle of about sixty degrees each with reference to the one opposite, by which means the lips of the speaker are brought close to all the diaphragms, so that, practically, each diaphragm is actuated with the same energy as a single one constructed in the ordinary way would be, by which means I am thus enabled to genti ate almost four times the electro-motive force that a single diaphragm would produce.

A battery may be employed arranged on circuit, either as shown in my application for Letters Patent filed October 29, 187 7, (Case 3,) or as in that filed January 17, 1878.

Fig. 3 shows all the helices as connected in one circuit with the line-wire. In consequence of this organization articulate words are transmitted with greater force and clearness than they are with a single diaphragm, or even with two diaphragms under the same circumstances.

Each telephone is a counterpart of the other, and the apparatus thus constitutes what I term a quadruplex or multipolar telephone.

The operation of the apparatus will readily be understood from the foregoing description. It is obvious that three, five, or even a greater number of telephones might be combined with a common mouth-piece on the system above described; but an even number is preferable, on account of their relations to the poles of the permanent magnets.

What I claim as of my own invention, and desire to secure by Letters Patent, is-

1. A multipolar telephone constructed, sub-"' stantially as hereinbefore set forth, with three or more diaphragms approximating each other.

at their edges, and connected with and arranged around a common mouth-piece at an angle of about sixty degrees thereto, to bring the lips of the speaker close to each diaphragm, and to increase the electro-motive force of the instrument.

2. The combination, substantially as hereinbefore set forth, of an electric circuit, a series of helices included therein, a correspondiug series of telephones, each mounted upon its respective pole of the magnets constituting thehandle oftheinstrument, a common monthpiece interposed between said magnets, and branch speaking-tubes connecting each diaphragm with the mouth-piece.

3. The combination, substantially as hereinbefore set forth, of an electric circuit, including a battery and a series of helices, a

soft-iron core for each helix, each core bei connected with its respective pole of the 1g manent magnets, (two in number,) arrange transversely to each other, and firmly unit to form a suitable handle, four diaphragm,

each mounted on its respective pole an ranged at a suitable angle relatively to others, with an interposed four-branch mom piece, each branch of which comes opposiiv the center of its respective diaphragm to o, erate each with the same electro-motive fOI'L from a common mouthpiece.

In testimony whereof I have hereunto su 

